The present invention relates to snap hooks of the type used in conjunction with positioning straps, lanyards and other personal fall protection devices used by linemen, window washers and other climbers while working at elevated work sites. More particularly, the invention relates to a keeper-equipped snap hook having a guard member which can be intentionally placed in an open position by the climber to allow ready actuation of the keeper and release of the hook, or intentionally placed in a closed position to prevent inadvertent actuation of the keeper and consequent release of the hook.
Snap hooks have come into wide use in connection with personal fall protection systems. One such fall protection system utilizes a positioning or pole strap to support a climber hands-free on a wooden pole or I-beam. The positioning strap is typically secured by a snap hook to a D-ring on a body belt on one side of the climber, passed around the pole or I-beam and secured by a snap hook to another D-ring on the other side of the climber. The climber can lean back supported by the strap and work hands free.
Another personal fall protection system utilizes a fall arrest lanyard designed to arrest a climber in a fall from an elevated work position. The lanyard, which is typically secured at one end to a support structure above the climber, is secured at its other end by a snap hook to a D-ring centered on a full body harness worn by the climber. In other systems wherein the lanyard is secured to a winch, the lanyard functions as a winch cable and can be used to suspend the user at an elevated work site, or to rescue the user from such a site.
Snap hooks used in these applications must not only be compatible with other components of the personal fall prevention system, and capable of supporting the weight of the climber, but must also be capable of being intentionally engaged and disengaged by the climber. One of the benefits of single-locking keepers is their ease of intentional engagement and disengagement.
Snap hooks designed for use with personal fall protection systems typically incorporate a metallic body formed with an open hook at one end, and a keeper, which closes the mouth of the hook to prevent unintentional removal of the hook from a D-ring. Typically in its single-locking form, the keeper comprises an arm which is pivotally mounted to the hook body and spring-biased into engagement with the tip of the hook. To install or remove the snap hook from, for example, a D-ring, the climber must first displace the keeper away from the hook tip to open the mouth of the hook so that the D-ring can pass through the mouth.
In its double-locking form, the keeper is similar to the single-locking keeper described above but includes a secondary latch element. In order to engage or disengage the hook, the double-locking keeper requires the climber to manually depress both the keeper and the secondary latch. The secondary manipulation that is required to intentionally engage and disengage the snap hook provides an additional measure of protection against an accidental disengagement of the snap hook.
In contrast, the present invention provides a snap hook having a single-locking keeper which can be readily released by the climber, wherein the keeper is protected from unintended or inadvertent release by a novel guard member. In particular, the guard member, which can be actuated by the climber at any time from an open position providing ready access to the keeper, to a closed position shielding the keeper from actuation, is U-shaped in cross-section so as to form a channel within which the keeper is received and protected when the guard member is closed.
Accordingly, it is a general object of the present invention to provide a new and improved snap hook.
It is a more specific object of the present invention to provide a snap hook of the type having a single-locking keeper which has an additional measure of protection against unintended or inadvertent actuation of the keeper.
It is another more specific object of the present invention to provide an improved snap hook of the type having a single keeper wherein a guard member protecting the keeper can be selectively positioned by a climber in a closed position, which not only prevents unintentional actuation of the keeper, but also protects the keeper from wear and damage; or in an open position, allowing ready actuation of the keeper to open the snap hook.